U.S. patent number 6,194,828 [Application Number 09/168,472] was granted by the patent office on 2001-02-27 for electrodeless gas discharge lamp having flat induction coil and dual gas envelopes.
This patent grant is currently assigned to Federal-Mogul World Wide, Inc.. Invention is credited to Jack D. Bodem, Jr., Robert L. Kohne.
United States Patent |
6,194,828 |
Kohne , et al. |
February 27, 2001 |
**Please see images for:
( Certificate of Correction ) ** |
Electrodeless gas discharge lamp having flat induction coil and
dual gas envelopes
Abstract
An electrodeless gas discharge light assembly includes a lamp
base (12) having a pair of light-transmitting lenses (14, 16)
supported in axially opposed relation to one another. An
electrodeless gas discharge light source (28) is mounted between
the lenses (14, 16) and comprises a generally flat spiral induction
coil (30) sandwiched between a pair of generally flat, planar
envelopes (32, 34) in which an ionizable gas (46) is contained.
Energizing the coil (30) inductively induces discharge illumination
of the gas (46) causing light to be emitted in axially opposite
directions through the lenses (14, 16) without obstruction by the
coil (30).
Inventors: |
Kohne; Robert L. (Noblesville,
IN), Bodem, Jr.; Jack D. (Kokomo, IN) |
Assignee: |
Federal-Mogul World Wide, Inc.
(Southfield, MI)
|
Family
ID: |
22611622 |
Appl.
No.: |
09/168,472 |
Filed: |
October 8, 1998 |
Current U.S.
Class: |
313/493; 313/160;
313/161; 313/634; 315/248; 315/39 |
Current CPC
Class: |
H01J
65/048 (20130101) |
Current International
Class: |
H01J
65/04 (20060101); H01J 001/62 (); H01J 063/04 ();
H01J 001/50 (); H01J 023/10 (); H01J 029/76 () |
Field of
Search: |
;313/156-57,491-493,234,607,627-28,631-32,634-35,637-643,161,160,17,25-26,31
;315/248,39,111.21,111.51,34,283,344,246 ;445/26,28
;362/84,267,328,329,335,310,317 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Patel; Nimeshkumar D.
Assistant Examiner: Haynes; Mack
Attorney, Agent or Firm: Reising, Ethington, Barnes,
Kisselle, Learman & McCulloch, P.C.
Claims
What is claimed is:
1. An electrodeless gas discharge lamp assembly comprising:
a lamp base;
a pair of light-transmitting lenses mounted on said base in axially
opposed relation to one another; and
an electrodeless gas discharge illumination source including:
generally flat spiral induction coil disposed between said lenses,
said induction coil having axially opposite sides, and
a pair of generally flat gas discharge envelopes each having an
ionizable gas scaled therein and each being disposed at one of said
axially opposite sides of said coil such that said gas is
inductively excitable to discharge illumination by operation of
said coil.
2. The assembly of claim 1 wherein said envelopes are generally
circular when viewed in the axial direction of said assembly.
3. The assembly of claim 1 wherein said source comprises a unitary
structure with said coil being sandwiched between said
envelopes.
4. The assembly of claim 1 including a battery power source
supported by said lamp base and operatively coupled to said
coil.
5. The assembly of claim 4 including an induction flasher circuit
coupled to said battery and said coil and operative to energize
said coil in timed pulses to produce corresponding flashes of light
from pulsed excitation of said gas.
6. The assembly of claim 5 wherein said circuit is supported by
said base.
7. An electrodeless gas discharge lamp assembly comprising:
a lamp base; and
an electrodeless gas discharge illumination source including:
a generally flat spiral induction coil supported by said base and
having axially opposite sides, and
a pair of generally flat gas discharge envelopes each having an
ionizable gas sealed therein and each being disposed at one of said
axially opposite sides of said coil such that said gas is
inductively excitable to discharge illumination by operation of
said coil.
8. An electrodeless gas discharge lamp source comprising:
a generally flat planar spiral induction coil having axially
opposite sides; and
characterized by a pair of generally flat planar light-transmitting
discharge envelopes disposed on said axially opposite sides of said
spiral coil, each of said envelopes having an ionizable gas sealed
therein which is inductively excitable to discharge
illumination.
9. The source of claim 8 wherein said discharge envelopes are
generally circular in shape.
10. The source of claim 8 wherein said envelopes are fixed to said
coil to provide a unitary sandwiched structure.
11. The source of claim 8 wherein said envelopes are convexly bowed
in axially opposite directions.
12. The source of claim 8 wherein said envelopes each have an
axially inner wall and an axially outer wall, said axially outer
walls having a light refracting pattern operative to diffuse light
transmitted through said outer walls.
13. A method of constructing and operating a double-sided emergency
flasher lamp having an electrodeless gas discharge illumination
source comprising:
preparing an electrodeless gas discharge illumination source
including a generally flat spiraled induction coil having opposite
axial sides and a pair of generally flat, planar light-transmitting
discharge envelopes disposed in axially opposite relation to one
another of the opposite sides of the coil, each envelope having
sealed therein an ionizable gas excitable to discharge illumination
during energization of the coil; and
mounting the illumination source on a lamp base and operating the
coil to inductively excite the gas to discharge illumination
producing light emitted from the envelopes in axially opposite
directions.
14. The method of claim 13 including mounting a pair of
light-transmitting lenses on the base axially outwardly of the
envelopes, and transmitting the light emitted from the envelopes
through the lenses.
Description
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates generally to electrodeless gas discharge
lamps and more particularly to the configuration and arrangement of
the induction coil and the envelope in which the discharge gas is
sealed.
2. Related Prior Art
Various arrangements for the induction coil and envelope of gas
discharge lamps are known and generally involve locating the
induction coil external of the envelope in closely adjacent
relationship therewith. The envelope often has a generally
cylindrical shape and is surrounded by a helically coiled induction
wire. When energized, the coil excites the gas within the envelope
to discharge illumination. The light which is emitted is blocked
somewhat in the radial direction by the induction coil but not in
the axial direction of the free end of the envelope. In many
applications that employ this type of coil and envelope
arrangement, the light is intended to be directed axially rather
than radially and thus the blockage of light in the radial
direction by the coil does not inhibit the performance of the
light.
In another known arrangement, a flat spiral induction coil is
supported adjacent a flat envelope and the light which evolves is
emitted forwardly of the envelope, but is blocked in the opposite
axial direction by the presence of the coil on the backside of the
envelope. In these known applications, such blockage of the light
by the coil does not present a problem since the light is intended
to be directed in the forward direction only.
In other lighting applications, such as emergency flasher beacon
lights of the type used, for example, on road construction pylons,
barriers, signs and the like, the light is directed in opposite
axial directions from a central incandescent light source through a
pair of axially oppositely disposed lenses of the device. The
incandescent lamp is often powered by a battery housed within a
lamp base which mounts the incandescent lamp and lenses. Both the
incandescent lamp and battery have a limited operating life, and as
such the present emergency flasher beacons require periodic
maintenance which adds cost and inconvenience to their usage.
It would be desirable to replace the incandescent lamp source with
an electrodeless gas discharge lamp source since it would eliminate
the presence of an electrode (i.e., a filament) which is the
principal cause for the failure of incandescent lamps. An
electrodeless gas discharge lamp source would further draw far less
power than a comparable incandescent lamp and its usage would
prolong the operating life of the battery, minimizing or altogether
eliminating the requirement for frequent maintenance associated
with the known incandescent beacon flashers.
There does not currently exist, however, an electrodeless gas
discharge light source suitable for such a double-sided lighting
application. In the case of the discharge lamps described above,
the induction coil in each case would interfere with the emittance
of light through at least one of the lenses and as such would
impair the performance of the light.
The present invention is directed at providing such an
electrodeless gas discharge lighting configuration suitable for
double-sided lighting applications.
SUMMARY OF THE INVENTION AND ADVANTAGES
An electrodeless gas discharge lamp assembly constructed according
to the present invention includes a lamp base, a pair of
light-transmitting lenses mounted on the base in axially opposed
relation to one another, and is characterized by an electrodeless
gas discharge illumination source including a generally flat spiral
induction coil disposed between the lenses having axially opposite
sides, and a pair of generally flat gas discharge envelopes
disposed between the lenses on the opposite sides of the coil each
having sealed therein an ionizable gas inductively excitable to
discharge illumination by operation of the coil.
Such an axially sandwiched arrangement of the coil and the two
envelopes has the advantage of exciting the gas in both envelopes
with a single coil, directing the light in axially opposite
directions without obstruction from the coil. While not limited in
its application, the invention is particularly well suited for
emergency flasher or beacon-type lights wherein the light from the
central source is transmitted in a)dally opposite directions
through the opposed lenses of the device. The electrodeless gas
discharge light source has the further advantage over conventional
incandescent lamp sources of minimizing or all together eliminating
the need to periodically replace the light source and prolonging
the life of the battery of such assemblies by operating at a
relatively lower rate of energy consumption.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention
will become more readily appreciated when considered in connection
with the following detailed description and appended drawings,
wherein:
FIG. 1 is a front elevation view of a lamp assembly constructed
according to the invention;
FIG. 2 is an enlarged cross-sectional view taken along lines 2--2
of FIG. 1;
FIG. 3 is an enlarged fragmentary front elevation view of the gas
discharge light source of FIGS. 1 and 2; and
FIG. 4 is a cross-sectional view like FIG. 2 but of an alternative
embodiment of the invention.
DETAILED DESCRIPTION
An electrodeless gas discharge lamp assembly constructed according
to a presently preferred embodiment of the invention is indicated
generally at 10 in the drawings and comprises a lamp base 12
mounting a pair of light-transmitting lenses 14, 16 supported in
axially opposite relation to one another defining a space 17
therebetween. The lenses 16 are generally flat and planar, although
they may be bowed somewhat convexly away from one another as
illustrated in FIG. 2. The lenses 16 lie in parallel planes and are
aligned along a central axis A of the assembly 10. The base 12 may
have a ring 18 that preferably is circular on which the lenses 16,
which are likewise preferably circular when view along the axis A
as in FIG. 1, are mounted by means such as the screws 20 of FIG. 1
or by other suitable means, including clips, fasteners, adhesives,
and the like.
The light assembly 10 depicted in FIGS. 1 and 2 is preferably an
emergency flasher or beacon light of the general type commonly used
to mark barriers, pylons, signs, equipment and the like to gain the
attention of those in the vicinity of the need to exercise
caution.
The base 12 has a housing 22 that may include separable upper and
lower housing portions 23, 24 defining a cavity 25 within the
housing. An on-board power source in the preferred form of one or
more batteries 26 is supported with the cavity 25 of the housing 22
so as to be protected from the elements and to provide electrical
power to the illumination source to be described below. The
separable housing portions 23, 24 provide access to the cavity 25
and the contents therein.
The lenses 14, 16 may be manufactured to include a light-diffusing
pattern or features 27 provided across the surface thereof for
diffusing the light transmitted through the lenses 14, 16 in
predetermined manner to achieve the desired lighting
characteristics.
According to the invention, an electrodeless gas discharge lamp
source 28 is provided in the space 17 between the lenses 14, 16 for
supplying light. The source 28 comprises a generally flat spiral
induction coil 30 axially sandwiched between a pair of generally
flat, planar light-transmitting envelopes 32, 34. As shown best in
FIGS. 2 and 3, the coil 30 and envelopes 32, 34 are preferably
united as a single, integrated subassembly wherein the coil 30 is
sandwiched in fixed relation between the two envelopes 32, 34 and
secured by means of a suitable adhesive or the like.
The coil 30 has axially opposite sides 36, 38 with respect to the
axis A. An inner surface 40 of the envelope 32 engages one side 36
of the coil, whereas an inner surface 42 of the other envelope 34
engages the opposite side 38 of the coil 30. The envelopes 32, 34
are preferably separate and distinct from one another each defining
an enclosed space 44 in which an ionizable gas 46 is sealed and
excitable to discharge illuminated when ionized by operation of the
induction coil 30 according to known principals. Any of a number of
ionizable gases suitable for electrodeless gas discharge lighting
applications may be employed, including, for example, neon, xion,
mercury, mixtures of these and/or others.
The envelopes 32, 34 may be fabricated of quartz or the like
suitable for transmitting light while retaining the gas 46 therein.
The envelopes 32, 34 preferably correspond in shape to that of the
lenses 14, 16, and thus are preferably circular when viewed in the
direction of the axis A. The envelopes 32, 34 are further
preferably concentric with the lenses 14, 16 and thus lie along the
axis A.
The coil 30 is coupled at its ends 48, 50 by lead wires 52, 54,
respectively, to an induction circuit 56 supported within the base
12. The circuit 56 is, in turn, electrically coupled to the energy
supply or batteries 26. The circuit 56 is operative to convert the
power supplied by the batteries 26 to induce the induction coil 30
to emit high frequency energy signals which act on the gas 46 to
ionize and excite the gas to discharge illumination. It is
preferred that the circuit 56 and coil 30 operation in the RF range
such that the coil 30 emits RF signals to drive the gas 46. The
principals of discharge illumination through high frequency
induction signals are well know to those in the art and thus will
not be elaborated upon here.
As illustrated by the directional light rays L of FIG. 2, the light
given off by the gas 46 in the envelopes 32, 34 will be directed
outwardly through the lenses 14, 16 in axially opposite directions
along the axis A without obstruction from the coil 30. In other
words, by locating the coil 30 axially between the envelopes 32,
34, there is a direct path for the light emitted from the envelopes
32, 34 to transmit through the lenses 14, 16 without encountering
the coil 30.
As mentioned earlier, the assembly 10 of the drawings is preferably
an emergency-type flasher. It is thus preferred that the circuit 56
include suitable flasher circuitry which would act to energize the
coil 30 in timed pulses in order to produce corresponding timed
illumination of the gas 40 to achieve the flashing effect. In other
words, the circuit 56 would operate to energize and then deenergize
the coil in repeated timed cycles to achieve an on/off flashing of
the light assembly 10.
The assembly 10 may further include a high frequency barrier 58 in
the preferred form of an RF screen surrounding the coil 30. The
screen 58 is operative to permit the passage of light therethrough
while blocking the transmission of the high frequency signals
generated by the coil so as to contain them within the assembly 10.
The screen 58 may be conveniently mounted along the inner surfaces
of the lenses 14, 16 and may, for example, be adhered thereto.
FIG. 4 shows an alternative embodiment of the invention wherein
like features are represented by like reference numerals, but are
offset by 100. The base 112 and circuitry 156 are the same as that
previously described. The principal difference is the elimination
of the lenses 14, 16 and the provision thereof of dual purpose
envelopes 32, 34 which serve not only to contain the gas 46 but
also serve as the lenses. In the illustration, the envelopes 132,
134 are generally flat and planar, yet are outwardly convex or
bowed away from one another to take on a lens shape. The extent of
bowing is exaggerated in the drawing figure for purposes of
illustration. The coil 130 is supported between the envelopes 132,
134 and serves as before to energize the gas 46 in both envelopes
32, 34. The envelopes 132, 134 may be formed with light-refracting
features 60 which act to diffuse the light transmitted through the
envelopes 132, 134 to achieve a desired lighting
characteristic.
Obviously, many modifications and variation of the present
invention are possible in light of the above teachings. It is,
therefore, to be understood that within the scope of the appended
claims, the invention may be practiced otherwise than as
specifically described. The invention is defined by the claims.
* * * * *